Fig. 1: Response of bdelloid rotifers to inoculation with the fungal pathogen R. globospora.

a Active A. ricciae; active and contracted A. vaga; composite of three A. ricciae corpses with fully developed R. globospora infections, differentiating into irregular resting spores and long conidiophores bearing spherical infectious conidia. b Proportion of rotifers killed by infection 72 hours after exposure to R. globospora. Points indicate replicate laboratory populations of A. vaga (n = 16 populations, 189 animals) and A. ricciae (n = 21 populations, 216 animals) exposed to 1000 conidia. Asterisks indicate a highly significant difference in infection mortality (relative risk test, RR = 3.74, 95% CI: 2.8–5.0, z = 8.76, P = 1.4e–25). Boxplots show median and interquartile range (IQR), and whiskers extend to the farthest datapoint from the median that remains within 1.5*IQR of Q1 and Q3 respectively. c Principal component analysis of overall gene expression across A. vaga and A. ricciae orthologous genes. The proportions of total variation accounted for by primary (PC1) and secondary (PC2) components are indicated in parentheses. Clustering of treatment groups across species indicates a strongly shared response in gene expression at T7 that diverges at T24, as A. ricciae moves further and more consistently along the PC1 axis than A. vaga. d Dynamics of gene up- and downregulation relative to control populations inoculated with UV-inactivated spores. Error bars around the observed number of genes in each category show 95% confidence intervals estimated from n = 100 bootstrap replicates (i.e., sampling across all genes with replacement 100 times, each time recalculating the number of shared genes in each category). Asterisks refer to significant differences in the proportion of the species’ respective genesets that are DE (Bonferroni-corrected Chi-square tests, d.f. = 1; n = 58,423 for A. ricciae, 66,273 for A. vaga; P = 9.7e–22, 5.4e–23, 4.7e–38 and 5.8e–8 respectively). e Extent of gene sharing in differentially expressed subsets across timepoints (within species). Values show the number of significantly DE genes shared by intersecting groups. Source data are provided as a Source Data file.